I have a 25/9 gear ratio and a half link chain and when I’m pedaling I will see the bottom of the chain start to loosen while the top stays tight. It makes me mad because when I bunnyhop I hear the chain hitting the bottom of the frame. What should I do?
A: When you pedal, all of the load carries over the top of the chain, between the teeth pulling up and over the rear cog and the teeth pulling the chain forward and down in the front, so it is totally normal for the chain to loosen on the bottom as it becomes the focus of all the chain slack and frame flex. If your chain slaps when you bunnyhop, this is a different issue because you are not pedaling. This is probably caused because your chain is simply a little loose. Try tightening your chain a bit and if you still get chain slap, try putting a zip tie on the frame right where the chain hits to eliminate that horrible “ting” every time you land.